Inspection method for display panel

Abstract

Disclosed herein is an inspection method for a display panel according to the present embodiments comprising driving the display panel so as to display a first color having a first reference brightness level; photographing the display panel to obtain a first image including at least one particle region; deriving a first particle brightness level of the particle region contrasted to the first reference brightness level from the first image; driving the display panel so as to display a second color having a second reference brightness level higher than the first reference brightness level; photographing the display panel to obtain a second image containing the particle region; deriving a second particle brightness level of the particle region contrasted to the second reference brightness level; and if the second particle brightness level is higher than the first particle brightness level, determining the particle region to be an internal particle.

What is claimed is: 
     
         1 . An inspection method for a display panel, comprising:
 driving the display panel so as to display a first color having a first reference brightness level;   photographing the display panel to obtain a first image including at least one particle region;   deriving a first particle brightness level of the particle region contrasted to the first reference brightness level from the first image;   driving the display panel so as to display a second color having a second reference brightness level higher than the first reference brightness level;   photographing the display panel to obtain a second image containing the particle region;   deriving a second particle brightness level of the particle region contrasted to the second reference brightness level;   comparing the first and second particle brightness levels to each other; and   determining the particle region to be an internal particle when the second particle brightness level is higher than the first particle brightness level.   
     
     
         2 . The inspection method for a display panel according to  claim 1 , wherein comparing the first and second particle brightness level to each other to determine the particle region to be an internal particle is performed under a condition in which the first and second particle brightness levels are above a reference value. 
     
     
         3 . The inspection method for a display panel according to  claim 1 , wherein the first and second particle brightness levels are each either the average brightness level or the maximum brightness level. 
     
     
         4 . The inspection method for a display panel according to  claim 1 , further comprising:
 irradiating external light towards the display panel; and   photographing the display panel to determine that the region in which the external light is reflected is an external particle.   
     
     
         5 . The inspection method for a display panel according to  claim 4 , further comprising:
 displaying a black color on the display panel;   photographing the display panel to determine a region having a color different than the black color to be the internal particle; and   excluding a region determined to be the external particle among the determined internal particles to set a remaining region to a first particle candidate group.   
     
     
         6 . The inspection method for a display panel according to  claim 5 , further comprising:
 comparing the first particle brightness level to the second particle brightness level to set the particle region determined to be the internal particle to a second particle candidate group.   
     
     
         7 . The inspection method for a display panel according to  claim 6 , further comprising:
 determining an overlapped region of the first and second particle candidate groups to be the internal particle.   
     
     
         8 . The inspection method for a display panel according to  claim 1 , wherein the first and second particle candidate groups contain position information of the region determined to be the external particle. 
     
     
         9 . The inspection method for a display panel according to  claim 1 , wherein the particle region is the region with a color different from background colors in the first and second images. 
     
     
         10 . The inspection method for a display panel according to  claim 1 , wherein the first and second colors are selected in gray scale. 
     
     
         11 . A system for inspection of a display panel, comprising:
 a loading unit,   an inspection unit,   a buffer unit, and   an unloading unit,   wherein the inspection unit comprises a stage,   a light source unit,   a control unit configured to drive the display panel so as to display a first color having a first reference brightness level and a second color having a second reference brightness level,   a photographing unit configured to photograph the display panel to obtain at least a first and second image including at least one particle region,   an image processing unit configured to derive a first particle brightness level of the particle region contrasted to the first reference brightness level from the first image, and derive a second particle brightness level of the particle region contrasted to the second reference brightness level;   a storage unit and   an output unit,   wherein the control unit is further configured to determine the particle region to be an internal particle when the second particle brightness level is higher than the first particle brightness level.   
     
     
         12 . The system according to  claim 11 , wherein the first and second particle brightness levels are above a reference value. 
     
     
         13 . The system according to  claim 11 , wherein the first and second particle brightness levels are each either the average brightness level or the maximum brightness level. 
     
     
         14 . The system according to  claim 11 , further comprising:
 wherein the light source unit is configured to irradiate external light towards the display panel; and   the photographing unit is configured to photograph the display panel to determine that the region in which the external light is reflected is an external particle.   
     
     
         15 . The system according to  claim 11 , further comprising:
 wherein the control unit is configured to display a black color on the display panel;   the photographing unit is configured to photograph the display panel to determine a region having a color different than the black color to be the internal particle; and   the control unit is configured to exclude a region determined to be the external particle among the determined internal particles to set a remaining region to a first particle candidate group.   
     
     
         16 . The system according to  claim 11 , further comprising:
 wherein the control unit is further configured to compare the first particle brightness level to the second particle brightness level to set the particle region determined to be the internal particle to a second particle candidate group.   
     
     
         17 . The system according to  claim 16 , further comprising:
 wherein the control unit is further configured to determine an overlapped region of the first and second particle candidate groups to be the internal particle.   
     
     
         18 . The system according to  claim 11 , wherein the first and second particle candidate groups contain position information of the region determined to be the external particle. 
     
     
         19 . The system according to  claim 11 , wherein the particle region is the region with a color different from background colors in the first and second images. 
     
     
         20 . The system according to  claim 11 , wherein the first and second colors are selected in gray scale.